The Importance of Water in the Sierra

In celebration of the Cal Middle School students joining us on Donner Summit this May for a program on water science, we were inspired to share some of our resources. Here’s a great explanation of the importance of water in the Sierra from the Water Education Foundation. We think it’s of the utmost importance for the students we teach, and for our friends, followers, and family, to understand the importance of these vital resources in the natural world.

Stretching along the eastern edge of the state, the Sierra Nevada region incorporates more than 25 percent of California’s land area and forms one of the world’s most diverse watersheds.

The Sierra Nevada is 450 miles long and 40 to 50 miles wide and includes granite cliffs, lush forests and alpine meadows on the westside, and stark desert landscapes at the base of the eastside. Its habitats support 66 percent of the bird and mammal species and about 50 percent of the reptile and amphibian species found in California including bighorn sheep, mule deer, black bear and mountain lions, hawks, eagles, and trout.

On average, 60 percent of California’s total annual precipitation – in the form of rain and snow – falls in the Sierra Nevada and a portion of the southern Cascades.

Snowmelt from the Sierra’s provides water for irrigation for farms that produce half of the nation’s fruit, nuts and vegetables, and also is a vital source for dairies, which have made California the largest milk producer in the country.

In addition, Sierra snowmelt provides drinking water to Sierra Nevada residents and a portion of drinking water to 23 million people living in cities stretching from the Bay Area to Southern California.

Find out more:

Sierra Nevada Water Cycle

The Sierra Nevada watershed provides much of California’s water because of its mountains, which “catch” eastern-moving clouds fattened by the Pacific before they reach Nevada.

In the Sierras, precipitation falls and accumulates during the winter months in higher elevations as snow. The snowpack acts as a natural reservoir that holds water until temperatures rise in late spring. In spring, the snowpack melts to provide significant runoff on the Sierra Nevada’s west slope and, to a lesser extent, on the Sierra Nevada’s eastern slopes.

The rain and snowmelt captured in the upper elevations flow to fill rivers and reservoirs and recharge groundwater basins.

Sierra snowmelt in spring typically contributes half of the total annual runoff from the region. After the high risks of floods have passed during spring, water is allowed to fill the reservoirs. By late summer, when natural river flows are at very low levels, water releases from the reservoirs provide much of the downstream water supply.

Find out more:

At Headwaters, Many of the students we work with, especially those from Sacramento or Bay Area schools, don’t have plentiful opportunities to visit the Sierra, but this is the place their water comes from! By engaging students in science learning opportunities, we also encourage them to think from the source, asking questions like: where do the resources I use daily actually originate? We hope sharing this information encouraged curiosity in you, too!

*This post was authored by the Water Education Foundation

Celebrate Science Sacramento 2019

On April 29, students from Met Sac High gathered at their school to share the scientific research they’d conducted during our overnight program. These students worked hard to develop hypotheses surrounding snow science, and then joined us in the Sierra to study over four feet of fresh snow!

The focus of the program was to investigate the structure of the Sierra snowpack and learn how this translates to water availability. Coming from Sacramento, the broader impact of these projects resonated with these students who live in the farming capital of the country.

At our Celebrate Science event, some of these students presented their findings. We were pleased to watch the confident and capable presenters share what they’d learned. We observed that in every case, the students had gained confidence in asking and answering questions, conducting scientific research, compiling and analyzing data, and presenting their findings. These skills were not as honed before they entered the program. We are so proud of them!

Here are some highlights of the research conducted by students:

-One group of students investigated patterns in snow density in the snowpack to better understand how much water was stored in the snow. They found that the older snow deeper in the snowpack was more dense than the newer snow at the top. On average, the 7 foot deep snowpack they measured was 25% water, which is equivalent to 21 inches of standing water!

-Two groups focused on snow temperature. While the snow may seem uniformly cold, these students found large temperature gradients within the snow. The snow nearest the ground was always close to 0 celcius. The snow closer to the surface was much colder between -6 and -10 celcius. Students hypothesized this was because the ground was warmer than the cold winter air we were experiencing.

Congrats to all the presenting students who worked hard on their research.

From pre and post program surveys it appears these students not only enjoyed the trip but also got a lot out of it. The percentage of students who said they were “very confident” in their ability to apply the scientific method increased 29%. Furthermore, the number of students who were “very interested” or “somewhat interested” in a science related career increased by 12%.

Many of these students had never seen snow before, so getting to test first hand where their water comes from was an impactful experience. Support from three groups made this trip affordable for the students. The Sierra Club gave this group a lodging scholarship to help cover room and board costs, Tahoe Donner Cross Country donated snowshoes to help students access their field sites in the deep snow, and support from 2018 Headwaters donors allowed us to further subsidize trip costs. Thank you to everyone who made this trip possible.